The purpose of this retrospective cohort study is to examine the association between occupational demands and the risk of adverse birth outcomes for active duty women in the US Army during the years 1980-1994. It will specifically assess the affects of occupational physical demands (lifting, carrying, body position) upon the risk of antenatal, perinatal, and newborn specific outcomes such as early fetal loss, spontaneous abortion, and low birth weight infants. The data to conduct this study will be taken from the Total Army Injury and Health Outcomes Database. This database contains demographics (including occupational and ergonomic exposures); hospitalization (including spontaneous abortions, preterm delivery, and low birth weight infants); and health risk (including smoking and nutrition) data on active duty women during the years 1980-1994. Additionally, the database contains Military Occupational Speciality as well as the US Department of Labor, Dictionary of Occupational Title codes. These categorizations will allow assessment of similarities in civilian and military occupational exposures linked to adverse birth outcomes. Incidence rates of events will be calculated and compared by age groups, race, rank, length of service, marital status, education, age at entry, medical (co-morbid and obstetrical) history, occupational groups, ergonomic exposure, and health risk factors. Analyses will include rate ratios, regression, and factor analysis where appropriate. Predictors of adverse birth outcomes will be identified. Ergonomic exposures may be the most common exposure of women in both traditional and non-traditional occupations. With the increasing number of women working outside of the home, coupled with those continuing to work through their pregnancies, understanding the effects of these exposures could help prevent adverse birth outcomes. This study will shed light upon preventing untold birth outcomes in both civilian and military women.